Receiving circuit



Feb. 11, 1930. E. F. POTTER RECEIVING CIRCUIT Filed Dec. 15. 1922 3 Sheets-Sheet 1 E 5P7 F P0271 211 l Feb. 11, 1930. F.- POTTERI 1,746,443

RECEIVING CIRCUIT Filed Dec. 15. 1922 s Sheets-Sheet 2 I Feb. 11; 1930. E. F. POTTER RECEIVING CIRCUII Filed Dec. 15. 1922 3 Sheets-Sheet 3 mm- .ZEJYFZUUPP Patented Feb. 11, .1930

UNITED STATES PATENT ore-ice, j

EARL F. POTTER, on ennncon, ILLINOIS, ASSIGNQB TO nLnoeG swrcccnnoeitp nun SUPPLY COMPANY, or CHICAGO, ILLINOIS, A conronar on on nnrnors RECEIVING GIRGUIT Application filed December 15, 1922. Serial No. 607,060,

one of its applications for receiving station purposes, although it is not to be limited to such receivingstation purposes, but is ap plicable to many situationsin which intenslfication and sharp tuning are ends sought.

Fig. 2 is a modification of Fig. 1 in which a feed-back coil is not employed.

Fig. 3 illustrates the invention as applied to a two element detector tube. a

In the said Fig. 1, A is the antenna, 1 a variable condenser, 3 a tuning coil with the switch lever 2 arranged to vary the number of turns of coil 3 that are operatively in circuit, while coil 4 is loose-coupled with coil 8. The grid. 9 is linked to the antenna lead through the usual grid condenser 6 and its associated grid leak. The plate 8 is connected to the plate battery 14 through the winding 4 and the primary 10 of a step up transformer. The return circuit for the plate 8 extends to filament 7 and the return side of battery, and the return circuit of the grid also extends through filament 7 in the usual manner.

The secondary winding 11 of the step up transformer connects to the grid ofthe amplifying tube 16 whose elements are associated with the receiving instrument B, and the batteries 13, 14 and 15 all in the usual and customary manner, the filament rheostats being indicated at 12 and 12.

It will be observed that the apparatus and elements 273, the condenser 1 andthe: inductance 5, the usual interaction of the 011% cuits. is preserved, while in addition thereto a byfpass is provided for a portion of the oscillations incomingover the. aerial A, the said by-pass being traced from A through inductance 5, to plate 8, thence to filament 7, (whereby the oscillations willebe rectified). and to ground. The, current-ifiow in the above path produces, naturally, changes OfiPO'EGlI- tial across the terminals ofcoils4 and 1Q, and these changesare inphase .withthe changes introduced by the plate as influenced in the usual manner by the, grid 9, being added to the said changes, and translated by the winding 4 to winding 3. into the amplifying processes of the system as a whole and form an integral part thereof. The by-pass arrangement described serves not only to increase the volume of reception but steadies the tube, giving clear and sharper reception of signals. A noticeable sharpness intuning resulting in the exclusion of undesired signals will beobserved by one practicing the invention.

. In Fig. 2 a modification of the circuit of Fig. 1 is shown in which a feed-back coil is not employed, the by-pass through the element 5 serving as before to impress rectified oscillations over an independent path upon the grid controlled signaling currents and serving like purposes, as explained in connection with Fig. 1.

In Fig. 3 I have illustrated my invention as applied to a system employing a two element or Fleming tube for detecting purposes. Such an organization yields a volume of reception approaching that of the system indi cated inFig. 1, increasing the sensitiveness and power of a two element tube very greatly. A wholly satisfactory explanation of the precise phenomena and reactions involved in producing the effect just noted has not been ascertained, but it appears that that portion of oscillations received upon antenna A that finds its way through the inductance 5, creates an oscillatory effect in the detector tube in conjunction with the oscillations reaching They are thus introduced a reactance effect at 3 ofa regenerative nature.

The phenomena of the invention is somewhat the same as if two antenna: were employed, one reaching the tube through the elements 34, and the other through the element 5.

What I claim as new and desire to secure by United States Letters Patent, is:

A receiving system including an oscillation receiver, a translating device including a primary and a secondary winding, said primary winding being connected to said receiver, a variable condenser between said primary windin and said receiver, a tuning device for varylng the number of turns of said primary winding that are effectively related to said secondary winding, a vacuum tube connected to the secondary winding of said translating device, a conductive connection extending from said oscillation receiver to said vacuum tube, and a continuously variable inductance for tuning said last circuit, said tuning device for said primary winding and said variable condenser constituting the sole means for controlling the oscillations furnished to said tube through said secondary winding. 7

Signed by me at Chicago, in the county of Cook and State of Illinois, this 13th day of December, 1922. I I

EARL F. POTTER. 

